Crimping device for shotgun shells



Allg 7, 1952 c. R. sHELToN 3,048,077

CRIMPING DEVICE FOR SHOTGUN SHELLS Filed Feb. 1, 1960 2 sheets-sheet 1 czz 11%. V VTOR j@ N l". BY 6'. .5ba/fan M f )554.7 f6, Afin/nay Aug. 7, 1962 c. R. sHELToN 3,048,077

CRIMPING DEVICE FOR SHOTGUN SHELLS Filed Feb. l, 1960 2 Sheets-Sheet 2 N\\w BY M f5 Jag. 14 J 'g. IJ' Aira/way ilnited ltates @arent 3,048,077 CRD/@WG DEVICE FR SHGTGUN SIELLS Clarence R. Shelton, 5534 Clark, Turner, Kans. Filed Feb. 1, 196i), Ser. No. 5,966

2 Claims. .(Cl. StG- 40) This invention relates to new and useful improvements in devices for crimping shotgun shells, and has particular reference to devices for producing what is commonly known as a star crimp, in which the substantially cylindrical open end portion of the shell casing, `after the charge has been inserted, is folded inwardly to close the end of said casing over the charge. The process' produces a pattern of radially extending folds in the circular end of the closed casing, from whence arises the name Lstar crimp. The end of the casing is then circularly indented, the indentation having a `diameter less than the shell `diameter whereby to leave a raised lip around said indentation, whereby to lock the folds in position.

The principal object of the present invention is the provision of a device which will perform this function quickly and efficiently, either on new ammunition, or When reloading used shell casings. It has been lfound that shotgun shells may be reloaded and reused several times without loss of eciency or safety. Y

Another object is the provision of a shell crimping device of the character described which will shape the exterior of the casing accurately to the exact form and size of new ammunition, in order that it will be received in and handled eiciently by the shotgun mechanism. The principal dimensions which must be controlled are the shell length, diameter land taper, and the exterior curvature of the lip at the forward end of the shell.

Another object is the provision of a shell crimping.

device of the character described which will avoid wrinlding, b-unching or other undesirable malformation of the cardboard of the shell casing, so as to provide a nished shell, even when reloading used ammunition, hav ing the neat, attractive appearance of new ammunition.

Other objects are simplicity and economy of construction, ease, convenience and dependability of operation,

and adaptability to crimp shells of various gauges and s1zes.

With theseobjects in view,l a swell as other objects which will appear in the course of the specification, reference will be had to the drawing, wherein:

iFIG. 1 is a side elevational view of a crimping device for shotgun shells embodying the present invention,

FIG. 2 is a side elevational View of a fully loaded and crimped shell, partially broken away,

FIG. 3 is a front-end view of the shell `as shown in FIG. 2,

FIG. 4 is a side elevational view of a shotgun shell before loading or crimping, partially broken away,

FIG. 5 is a longitudinal sectional view of the forming sleeve which constitutes aportion of the device 4forming the subject matter of the present invention,

FIG. 6 is an end view of the sleeve shown in FIG. 5,

FIG. 7 is an enlarged fragmentary sectional view taken on line VIL-VII of FIG. 1, showing a shell positioned in the sleeve and placed between the head plates of the press preparatory to the initial crimping operation,

BIG. 8 is a view similar to FIG. 7 but with the initial crimping operation completed,

FIG. 9 is an enlarged fragmentary sectional view taken on line lX-IX of FIG. l, showing the parts positioned preparatory for the iinal crimping operation,

IFIG. 10 is a View similar to FIG. 9, but with the nal l crimping operation completed,

ice

crimping operation as performed by the modified structure of FIG. 11, showing respectively the completion of the initial crimping operation, positions preparatory to the nal crimping operation, an intermediate stage of the nal crimping operation, and the completion of the final crimping operation.

Like reference numerals apply to similar parts throughout the several views, and the numeral 2 applies to a shotgun shell. Generally, as best shown in FIG. 2, said shell comprises a cup-shaped metal base 4 'having a rim 6, and which it will be understood carries the primer, not shown, and a pasteboard or paper body portion S which is tubular and generally cylindrical, though tapering slightly toward its forward end. After the powder and shot charge of the shell, indicated at 10, has been inserted in the body, the star crimping process involves folding the walls of the forward end portion of the body inwardly over the charge, the folding occurring on lines l2 eventually radial to the shell as shown in FIG. 3, whereby to present a neat, finished appearance. Finally, the forward end of the shell body is indented circularly as indicated at lli, said indentation being of smaller diameter than the shell body so as to leave a raised rib 16 around the indentation. This locks the folds firmly in position. When performing the crimping operation, either in new ammunition or in reloading` used ammunition, it is important that the diameter, length and taper of the shell be accurately controlled in order that the shell will engage the gun mechanisms properly. Also, particularly in ammunition for automatic guns, it is important that the external curvature of lip 16, as indicated at 1S, be controlled accurately at a specified radius, in order that the shell can be inserted properly in the gun chamber by the shell handling mechanism thereof.

The device for performing the crimping operation according to the present invention includes a forming sleeve Ztl best shown in FIGS. 5 and 6. Said sleeve is formed of steel or other durable material and has a bore formed longitudinally therethrough. One end portion of said bore forms a `chamber Z2 conforming accurately to the desired external contour of the finished shell. That is, it iS circular and tapered slightly toward its upper end, and is provided at its extreme lower end with an enlarged section 24 for receiving the rim 6 of the shell. The portion of the sleeve bore above chamber 22, which is designated by the numeral 26, is cylindrical and coaxial with chamber 22, but is of smallerdiameter than said chamber, its diameter being equal to or slightly less than the Vminimum external diameter of shell lip 16. The shoulder 28 between chamber 22 and bore 26 is spaced above the lower end of the sleeve a distance equal to the total length of the finished shell, and the walls of chamber 22 are arcuately curved, as indicated at 30, to merge with shoulder 23, the radius of this curvaturebeing the exterior curvature desired on lip 16 of the shell.

The sleeve 2li` is utilized in any suitable press device, as for example the press shown in FIG. l constituting a base 32, an upright standard 34 affixed to said base, a horizontal lower press plate 36 affixed rigidly on Said standard, a horizontal upper press plate 3S having a hub liti carried for vertical sliding movement on standard 34, and an operating lever 42 pivoted intermediate its ends to huh 4h at 4e, and pivotally connected at one end by means of link 45 to a post 48 aihxed to base 32. It will be readily apparent that by operating lever 42, the heads 36 and 38 maybe moved toward and from each other.

in use, an open shell casing as shown in FIG. 4 is first loaded by inserting the desired powder and shot charge lil therein, and is then inserted, open end first, into the lower or chamber end of sleeve Zii, into which it will advance freely until it strikes the chamber curvature 30 adjacent shoulder 22S. The base 4 of the shell is then rested on lower press plate 36, and the sleeve and shell are brought into alignment with an initial forming die Si? carried by upper press plate 38. The initial forming die has the form of a cylindrical plunger with a vertical :i3-iis, andis of a diameter to fit slidably in the bore 26 of Sleeve Ztl. It is provided with a threaded extension 52 engaged in plate 38, and secured rigidly therein by lock nut 54. The die extends below plate 38 a distance equal to the distance between shoulder 28 and the upper end of the sleeve. The lower face of the die has a conical depression 56 formed therein as best shown in FIG. 7.

The two plates are then urged toward each other, as by operating lever d2, whereupon die S enters the upper end of the sleeve till its lowermost edge is in registry with shoulder 28 of the sleeve, at which time plate 33 engages the upper end of the sleeve. Continued downward movement of plate 38 forces sleeve 2d downwardly over the shell until the lower end of said sleeve engages plate 36, as shown in FIG. 8. During this latter movement the curvature 30 of chamber 22 and the inclined walls of conical depression 56 fol-d the forward end portion of the shell wall inwardly, also as indicated in FIG. 8. It is of course important that in folding inwardly, the folding or creasing occur on the radial lines 12 as indicated in FIG. 3. If the shell has been previously fired and is being reloaded, the creases will already exist in the paper, and the proper folding will occur automatically. If a new and previously unused shell is being loaded, it will be necessary to use a die Si? which has a star pattern of raised ridges in the conical depression 56 thereof. Such a special die is not pertinent to the essential features of the present invention, however, and is not here shown.

Upper press plate 38 is then raised to retract die 5f) from sleeve 2t), and then the sleeve and the shell it contains are shifted on lower press plate 36 into alignment with a iinishing die 58 also carried by upper plate 3S. Die 58, like die G, is provided with a threaded extension 60 engaged in plate 3S and secured by -a lock nut 62. It is also generally cylindrical in form, the upper portion thereof being of a diameter to be received slidably in bore 26 of the sleeve, and the lower portion 64 thereof being reduced to a diameter equal to the `desired internal -diameter of shell indentation 14. Said die extends below plate 38 a distance equal to the distance between shoulder 2S and the upper end of sleeve 20, plus the desired depth of indentation 14. Press plate 33 is then lowered till die diel 58 enters bore 26, and further till plate 3S engages the upper end of sleeve 20, as shown in FIG. l0. During the latter portion of this movement, the lower end of die 58, which is flat and at right angles to the axis of the die, engages the portions of the shell wall which were previously turned in by forming die Si), and turns them in still further to close the end of the shell over the charge. The tinal portion of the die movement forces the face of the die below the level of shoulder 28, whereby the end indentation 14 in the shell casing is formed to lock the folds in place. The crimping of the shell is then complete, and the shell may be pushed out of sleeve by any suitable plunger means which forms no part of the present invention and is Vnot here shown.

The angle of the conical depression 56 of forming die 50 has been found to be quite critical, and for best results the total included angle of the cone should be rather accurately at 1.12 degrees. If the angle is larger in any substantial degree, the paper shell walls are turned in too abruptly, with the result that they tend to curl inwardly away from the depression walls, rather than lying flat against the depression walls as in FIG. 8. If such curling occurs, then finishing die S8 cannot close the shell properly, but will cause the inturned wall to fold under, leaving a central opening in the end of the Shell through which shot could trickle out. If the cone angle is smaller than 112 degrees to any substantial degree, then the walls are folded inwardly to an insuicient extent, with the result that the finishing die 58 will crush or buckle said walls rather than folding them inwardly as described. For these reasons, which have been determined by veryextensive experimentation and testing, the specific included angle of conical depression 58 is believed to be a pertinent and important feature of my invention.

The structure thus far described is acceptable in that it produces thoroughly serviceable ammunition, but has been found objectionable in that with its use there appears unsightly wrinkles and bunching of the shell case paper, particularly around the edges of indentation 14, and in the lip 16 of the shell. Such unsightly wrinkles and other deformations seriously affect the confidence users are willing to place in the ammunition, and hence its saleability. The wrinkles have been found to result from the fact that at one time in the crimping operation an excess length of the shell is contained in the sleeve 20. That is, referring to FIGS. 8 and 9 it will be seen that opposite points of the shell wall are brought into contact at the centerline of the shell by forming die 50 even while the folded wall portions are still inclined obliquely to said centerline. Thus when said inclined wall portions are forced still farther downwardly into a horizontal position by the finishing die, the inner edges of the wall are forced into interfering relation at the centerline of the shell, with the result that they tend to wrinkle or buckle under the pressure. The excess shell length is necessary in order i that the shell will be properly closed at its center after indentation 14 is made. The excess length is eventually absorbed in forming lip 16, but does exist and cause wrinkling and bucking particularly as the lower face of die 58 approaches and traverses shoulder 28. The unsightly wrinkles persist even after indentation 14 is completed. It does not solve the problem simply to cause forming die 50 to turn in a shorter shell length, so that opposite points of the shell wall would just meet at the centerline of the shell as the lower face of die 58 traverses shoulder 28, since then there would be insufficient wall length to both form the lip 16 and close the end of the casing completely. Failure to closecompletely would perhaps permit leakage of shot, and would in any event be unsightly. Failure to form lip 16 completely would change the length of the shell and destroy the curvature 18 necessary at its forward end, and thereby seriously inipair the usefulness of the ammunition.

The modification of the device shown in FIGS. 1l-15 solves these problems largely by withholding a portion of the shell length from sleeve 20 until after the wall has been folded into a horizontal position, then forcing the remainder of the shell into the sleeve to form the lip 16. The structure varies from that shown in FIGS. 1 and 5-10 principally in the provision of a shallow recess 66 in the upper surface of lower press. plate 36 in axial alignment with forming die 68, which corresponds to die 50 of FIGS. 1, 7 and 8. Said recess is circular, having a diameter greater than that of shell rim 6, but less than the external diameter of the lower end of sleeve 20. The depth of the recess is equal to the desired depth of shell indentation 14. Forming die 68 differs from die S0 only in that conical depression 70 thereof is of smaller maximum diameter than the die, thereby leaving a flat annular face 72 surrounding the depression, for a purpose which will presently appear. The finishing die 74, which corresponds to die 53 of FIGS. l, 9 and 20, has a diameter throughout its length equal to the diameter of indentation 14, and bore 26 of sleeve 20 is of corresponding diameter.

When the loaded shell is slipped into sleeve chamber 22 and set on press plate 36 in alignment with forming die 68, the rim 6 of the shell rests in depression 66, as shown in FIG. ll. Upper press plate 38 is then lowered as before to insert die 68 into sleeve 20 till the lower end of the die is substantially flush with shoulder 28, at which time plate 38 engages the sleeve and forces it downwardly over the shell. However, since sleeve 20 cannot enter recess 66, said sleeve is engaged and arrested by plate 36 while a portion of the shell still projects from the lower end of the sleeve. This projection of course equals the depth of recess 66, and hence the depth of indentation 14 to be formed eventually in the end of the shell. The parts then have the position shown in FIG. 12. Downward movement of the sleeve over the shell has as before caused the upper portion of the shell casing wall to be folded inwardly on itself toward the centerline of the shell, as clearly shown. However, due to the portion of the shell withheld from the sleeve by recess 66, the forming die does not bring opposite points of the casing wall into contact with each other as was the case in FIG. 8, but leaves said opposite points spaced apart as clearly shown. In other words, the forming die does not completely close the end of the shell, but leaves it slightly open.

Thus, when the sleeve is then positioned beneath finishing die 68, as shown in FIG. 13, and press plate 38 is lowered to introduce die 74 into the sleeve, the at lower face of said die first engages the turned-in portion of the shell casing and `forces it into ahorizontal position. The length of the shell withheld :from the 1. A crimping device for folding the forward end portion of the casing of a generally cylindrical shotgun shell inwardly to close said shell and to indent the folded-in portion of said casing circularly to a diameter less than that of the shell, whereby -to provide a raised lip surrounding said indentation, said device comprising generally parallel and planar first and second press plates, means for moving said plates relatively closer together, a tubular sleeve adapted to be positioned between said plates with its axis parallel to the direction of relative movement thereof, whereby to limit the movement of said plates toward each other by engagement of its respective ends with `said plates, said sleeve having a bore formed axially therethrough, one end por-tion of said bore forming a chamber conforming to the desired exterior size and shape `of a finished shell, and being adapted to receive an open shell forward end first therein, and the other end portion 4of said bore being cylindrical and o-f reduced diameter, and constituting a die guide, the

sleeve by recess 66 is such that the casing will be closed,

that is, diametrically opposite points of the casing will be brought into engagement at lthe centerline of the shell, just as the lower face of die 74 reaches shoulder 28 of the sleeve. Since there is no excess shell length in the sleeve at this time, there will be no Vtendency to cause crumpling, wrinkling or buckling of the casing wall in its own plane. Continued movement of die 74 past shoulder 28 into chamber 22 causes Vthe start of indentation 14 and a beginning of the lip 16, as shown in FIG. 14. When die 74 is fully inserted, plate 38 engages the upper end of sleeve 20, and continued movement of plate 38 forces the sleeve downwardly into full engagement with the shell, said shell now being supported by a planar, non-recessed portion of plate 36, all as shown in FiG. l5. The movement of the shell into the sleeve at -this time forces the casing wall into the annular space Ibetween the lower end portion of die 74 and the arcuate shoulder 30 of chamber 22, thereby building the lip 16 up to its full height and molding it rmly to the desired contour.

The at annular face 72 of forming die 68 forms a corresponding shaped surface 76 in the shell casing (see FIGS. l2 and 13) between the inclined portions formed by conical depression 70 of die 68 and the arcuately curved portion `formed by portion 30 of the sleeve. It will be seen that this at portion 76 of the casing is eventually and iinally disposed at the periphery of indentation 14 of the shell, immediately adjacent lthe cylindrical wall thereof. The annular flat 72 of die 68 tends to prevent the f.folds formed by conical depression 70, or any extension of said folds which might be caused by the stiffness of the casing material, from extending into that portion of the casing Wall which eventually will form the shell lip 16. Thus another possible cause of folding or wrinkling the lip is eliminated, and a smoother, more pleasing rappearance is accomplished. The threaded extension by which each of the various `forming and finishing dies is mounted in upper press plate 38, and the associated lock nuts, permit the accurate adjustment of said dies to laccommodate the device to receive ammunition of slightly different lengths, and to engage properly in sleeves of slightly different lengths.

While I have shown and described certain specific embodiments -of my invention, it will be readily apparent that many minor changes of structure and operation could be made without departing from the spirit of the invention as defined by the scope of the appended claims.

What I claim as new `and desired to protect by Letters Patent is:

guide and chamber portions of said bore being separated by a curved shoulder facing toward the chamber end of the sleeve, a cylindrical forming die affixed to'said rst plate and projecting at right angles therefrom toward said second plate to a distance substantially equal to the axial length of said die guide, and being of a diameter to -tit slidably in said guide, said Iforming die having a conical depression formed in the outer end thereof coaxially therewith, said second plate having a circular, hat-bottomed recess -formed in the surface thereof, facing said first pl-ate, and in axial alignment with said forming die, said recess having a depth substantially equal to the depth of the indentation to be formed in the shell casing, and having a diameter greater than that of the base of said shell but less than the external diameter of said sleeve, 4and a generally cylindrical iinishing die also iixed in said first plate, in spaced apart relation from said forming die, and extending at right angles therefrom toward said second plate to a distance substantially equal to the axial length of said guide plus lthe depth of the indentation to be formed in the end of said shell, and being of a diameter to engage slidably in said guide, .the outer end of said finishing die being planar and yat right angles to the axis thereof, and corresponding in diameter vto Ithe desired diameter of said indentation, said sleeve Ibeing adapted to be moved on said lsecond plate to receive said forming and finishing dies successively in the guide portion thereof, -said lirst and second plates being uniformly spaced apart at all points except at the recess in said second plate.

2. A crimping device as recited in claim 1 wherein said conical depression in the outer end of said forming die has a maximum diameter less than the diameter of .the die, ywhereby to leave a flat annular face surrounding said depression.

References Cited in the tile of this patent UNITED STATES PATENTS OTHER REFERENCES American Rifleman, vol. 106, No. 4, April 1958, pages 34, 35. 

